Field of the Invention
The present invention relates to a sealing resin composition and a sealing sheet, particularly a sealing resin composition and a sealing sheet, which are preferable for sealing photoelectric conversion elements such as luminescence elements (e.g., organic EL (Electroluminescence) element and the like), light receiving elements (e.g., solar cell etc.), and the like, and the like.
Discussion of the Background
Organic EL (Electroluminescence) element is attracting attention in recent years, which is a luminescence element using an organic substance as a luminescence material and capable of providing high-intensity luminescence at a low voltage. However, since organic EL element is extremely weak to the moisture, the luminescence material (luminescence layer) is deteriorated by the moisture, problems occur in that the brightness decreases, luminescence is not produced, the interface between the electrode and the luminescence layer is detached due to an influence of moisture, and the metal is oxidized to be highly resistant. Therefore, to shut off the inside of the element from the moisture in the outside air, for example, the organic EL element is sealed by forming a sealing layer composed of a resin composition to cover the entire surface of a luminescence layer formed on the substrate.
A resin composition used for sealing an organic EL element is requested to have not only high barrier property (resistance to moisture permeability), but also high adhesive strength. In addition, it is requested to show high transparency when light is extracted from the sealed face (surface of sealing layer). It is conventionally proposed to add, as this kind of resin composition, particles of talc and hygroscopic metal oxides such as calcium oxide, magnesium oxide, strontium oxide, barium oxide and the like to a resin composition to realize high barrier property and high adhesive strength (e.g., patent document 1: JP-A-2011-84667). However, when such hygroscopic metal oxide is used, transparency of resin composition is impaired and high transparency cannot be achieved.